Button: 4
Scroll Wheel: 1
Optical Resolution: 800/1200/1600 dpi
Interface: Wireless USB
Size:

3  3/8( L )  x 2  3/4( W)  x 1 1/4 (H )inch
90 ( L ) x 45( W ) x 35 ( H )mm
Weight: 0.09 (KG)/ 0.20 (LBS)
System Requirements:

IBM PC or compatible
Available USB Port
Windows ME/2000/XP/Vista/7/8